CN103179715A - Constant current drive circuit of large-power light-emitting diode (LED) - Google Patents
Constant current drive circuit of large-power light-emitting diode (LED) Download PDFInfo
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- CN103179715A CN103179715A CN2011104277857A CN201110427785A CN103179715A CN 103179715 A CN103179715 A CN 103179715A CN 2011104277857 A CN2011104277857 A CN 2011104277857A CN 201110427785 A CN201110427785 A CN 201110427785A CN 103179715 A CN103179715 A CN 103179715A
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- drive circuit
- constant current
- current drive
- constant
- operational amplifier
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Abstract
The invention discloses a constant current drive circuit of a large-power light-emitting diode (LED). The constant current drive circuit is composed of an operational amplifier and a metal-oxide -semiconductor field effect transistor (MOSFET) serving as a core. An adjustable voltage signal Vs output by a digital-analogue (D/A) converter is introduced to the in-phase input end of the operational amplifier to enable the constant current drive circuit to form a controllable constant current source, and the reverse input end of the operational amplifier is connected with a sampling resistor Rf. The constant current drive circuit has the advantages of being high in stability, reliability and output quality, and application of the drive circuit of the large-power LED is achieved.
Description
Technical field
The present invention relates to the constant-current drive circuit of a kind of constant-current drive circuit, particularly a kind of great power LED.
Background technology
So-called constant-current source refers to go to zero corresponding to the curent change that certain voltage and variations in temperature produce, and has the current source circuit of constant current value and very high dynamic output resistance.A desirable dc constant current power supply will produce a constant current that has nothing to do with its both end voltage.No matter how high the voltage value at constant-current source two ends is, its electric current is fixed as all the time.The equivalent internal resistance of desirable constant-current source is infinitely great, that is to say, it can export infinitely-great voltage.The voltage at constant-current source two ends must determine according to the external circuit that it connects, and single we can not determine the voltage at its two ends by constant-current source, and can only determine its current value.
And desirable constant-current source great power LED Drive Control Technique is non-existent, because the equivalent internal resistance of actual constant-current source can not be infinity, so its output voltage is also always limited, only allows in the voltage range of a regulation as constant-current source work.
Obviously, if load resistance is fixing all the time, it directly can be connected across source of stable pressure output and brings in the acquisition constant current.Yet, many actual loadings that need constant current, their equivalent internal resistance all changes in the course of the work.Therefore, we can not replace constant-current source with stabilized voltage power supply in the great power LED Drive Control Technique.
Summary of the invention
The object of the invention is to provide the constant-current drive circuit of the great power LED of a kind of high stable, highly reliable, high output quality.
In order to realize above-mentioned purpose, technical scheme of the present invention is: a kind of constant-current drive circuit of great power LED, it coordinates MOSFET by operational amplifier is that core consists of, and introduces at the in-phase input end of described operational amplifier the adjustable voltage signal V that is exported by D/A
s, make it become controlled constant-current source, connect sampling resistor R at reverse input end
f
Circuit of the present invention has the characteristics of high stable, highly reliable, high output quality, can satisfy the application of high-power LED drive circuit.
Description of drawings
Accompanying drawing is constant-current drive circuit schematic diagram of the present invention.
Embodiment
As shown in drawings, described constant-current drive circuit is that operational amplifier cooperation MOSFET is the constant-current drive circuit of core.In-phase input end at described operational amplifier is introduced the adjustable voltage signal V that is exported by D/A
s, make it become controlled constant-current source, connect sampling resistor R at reverse input end
f
Operational amplifier is operated in the deep negative feedback states, and it coordinates power MOSFET to follow input reference voltage V by feedback
s, power MOSFET is connected with the base stage of operational amplifier, is used for increasing drive current.When the in-phase end input voltage of operational amplifier is constant, due to degenerative existence, guaranteed the constant of output voltage, be constant current thereby make the electric current of the LED load of flowing through.The output current of constant-current source directly depends on output voltage and the sampling resistor R of D/A
f, ratio.
Owing to having used operational amplifier in feedback element, the loop gain of feedback control loop strengthens, depth of feedback strengthens, thereby more general current-series negative feedback triode current source performance index improve a lot, be a kind of high-quality current source circuit, the output impedance of this circuit is very approaching desirable infinitely great.
As current sampling resistor R
f, on electric current become large, namely compare amplifier end of oppisite phase voltage with reference voltage and uprise, amplifier is just adjusted output so, makes the V of power MOSFET tube
GThe voltage step-down, thus electric current is lowered, and the electric current of finally realizing flowing through on current sampling resistor is by reference voltage V
sControl.
Above-described embodiment does not limit the present invention in any way, and every employing is equal to replaces or technical scheme that the mode of equivalent transformation obtains all drops in protection scope of the present invention.
Claims (1)
1. the constant-current drive circuit of a great power LED, it coordinates MOSFET by operational amplifier is that core consists of, and it is characterized in that: introduce adjustable voltage signal V by D/A output at the in-phase input end of described operational amplifier
s, make it become controlled constant-current source, connect sampling resistor R at reverse input end
f
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011104277857A CN103179715A (en) | 2011-12-20 | 2011-12-20 | Constant current drive circuit of large-power light-emitting diode (LED) |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011104277857A CN103179715A (en) | 2011-12-20 | 2011-12-20 | Constant current drive circuit of large-power light-emitting diode (LED) |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN103179715A true CN103179715A (en) | 2013-06-26 |
Family
ID=48639261
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011104277857A Pending CN103179715A (en) | 2011-12-20 | 2011-12-20 | Constant current drive circuit of large-power light-emitting diode (LED) |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103179715A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104052317A (en) * | 2014-07-03 | 2014-09-17 | 郑州日产汽车有限公司 | Voltage simulator of battery of electric vehicle |
| CN104219842A (en) * | 2014-08-29 | 2014-12-17 | 深圳市奋勇光电有限公司 | LED constant-current unit |
| CN104639069A (en) * | 2015-02-13 | 2015-05-20 | 何山暐 | Radio-frequency amplifying circuit and power limit module thereof |
| CN106093860A (en) * | 2016-07-18 | 2016-11-09 | 中国地质大学（武汉） | A kind of LED indoor localizing emission system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101221454A (en) * | 2007-12-04 | 2008-07-16 | 南京大学 | Direct current bias constant-current supply |
| CN101630170A (en) * | 2009-08-18 | 2010-01-20 | 上海艾为电子技术有限公司 | Adaptive control device internally and externally set with constant current and method thereof |
-
2011
- 2011-12-20 CN CN2011104277857A patent/CN103179715A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101221454A (en) * | 2007-12-04 | 2008-07-16 | 南京大学 | Direct current bias constant-current supply |
| CN101630170A (en) * | 2009-08-18 | 2010-01-20 | 上海艾为电子技术有限公司 | Adaptive control device internally and externally set with constant current and method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 张玉宝，曹会云，张滨: "基于单片机的数控恒流源的设计", 《电测与仪表》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104052317A (en) * | 2014-07-03 | 2014-09-17 | 郑州日产汽车有限公司 | Voltage simulator of battery of electric vehicle |
| CN104219842A (en) * | 2014-08-29 | 2014-12-17 | 深圳市奋勇光电有限公司 | LED constant-current unit |
| CN104219842B (en) * | 2014-08-29 | 2017-09-29 | 深圳市奋勇光电有限公司 | Led constant current device |
| CN104639069A (en) * | 2015-02-13 | 2015-05-20 | 何山暐 | Radio-frequency amplifying circuit and power limit module thereof |
| CN104639069B (en) * | 2015-02-13 | 2017-08-11 | 康希通信科技（上海）有限公司 | A kind of radio frequency amplifying circuit and its power limitation module |
| CN106093860A (en) * | 2016-07-18 | 2016-11-09 | 中国地质大学（武汉） | A kind of LED indoor localizing emission system |
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|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C05 | Deemed withdrawal (patent law before 1993) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20130626 |